Application Ser. No. 250,224 filed May 4, 1972, now U.S. Pat. No. 3,829,688 by Harrison H. Barrett discloses a nuclear shadowgraph system for forming large area nuclear images with zero order data components suppressed by using an off-center section of a Fresnel zone plate and with the low frequency components enhanced by the addition of a carrier frequency through a second nuclear mask. Such a system substantially increases the spatially detected count rate over conventional collimated or pinhole scanned imaging systems. However, as pointed out in said application, for higher energy radiation the relatively thick scintillometer crystals limit the definition, or upper frequency response, of the spatial detector system, and commercially available spatial detector amplifier systems, such as the Anger camera, having upper spatial frequency limits below the spatial frequency desired for a carrier frequency can be used.